Modern medicine uses a variety of monitoring systems and methods, some of which require attachment of a small capsule to a tissue or organ inside the body. One such use is in monitoring Gastroesophageal reflux for diagnosing gastroesophageal reflux disease. Gastroesophageal reflux occurs when stomach acid intermittently surges into the esophagus. It is common for most people to experience this acid reflux occasionally as heartburn. Gastroesophageal reflux disease (GERD) is a clinical condition in which the reflux of stomach acid into the esophagus is frequent enough and severe enough to impact a patient's normal functioning and/or to cause damage to the esophagus.
In the lower part of the esophagus, where the esophagus meets the stomach, there is a muscular valve called the lower esophageal sphincter (LES). Normally, the LES relaxes to allow food to enter into the stomach from the esophagus. The LES then contracts to prevent stomach acids from entering the esophagus. In patients afflicted with GERD, the LES relaxes too frequently or at inappropriate times, allowing stomach acids to reflux into the esophagus.
The most common symptom of GERD is heartburn. Acid reflux also leads to esophageal inflammation, which causes symptoms such as painful swallowing and difficulty swallowing. Pulmonary symptoms such as coughing, wheezing, asthma, or inflammation of the vocal cords or throat may occur in some patients. More serious complications from GERD include esophageal ulcers and narrowing of the esophagus. The most serious complication from chronic GERD is a condition called Barrett's esophagus in which the epithelium of the esophagus is replaced with abnormal tissue. Barrett's esophagus is a risk factor for the development of cancer of the esophagus.
Accurate diagnosis of GERD is difficult but important. Accurate diagnosis allows identification of individuals at high risk for developing the complications associated with GERD. It is also important to be able to differentiate between gastroesophageal reflux, other gastrointestinal conditions, and various cardiac conditions. For example, the similarity between the symptoms of a heart attack and heartburn often lead to confusion about the cause of the symptoms. Esophageal manometry, esophageal endoscopy, and esophageal pH monitoring are standard methods of measuring esophageal exposure to stomach acids and are currently used to diagnose GERD.
One example for an esophageal pH monitoring device is the Bravo™-brand pH monitoring system, available from Given Imaging Ltd. of Yoqneam, Israel. In the currently available Bravo™ pH monitoring system, an autonomous pH monitoring capsule is attached to the esophagus in order to monitor esophageal pH. A delivery device that anchors the capsule to the esophagus has a single actuator. However, when operating the Bravo™ delivery device, two different motions are required from the operator; a first motion of the actuator anchors the capsule at a specific location along the esophagus, and a second motion of the actuator releases the capsule from the delivery device. Although operating the single actuator is not complicated, it is not intuitive for some users, and requires some training for proper use. Therefore, there is a need for a simpler delivery device for anchoring a monitoring capsule within the body lumen.